672401781 has 6 divisors (see below), whose sum is σ = 971247030. Its totient is φ = 448267848.

The previous prime is 672401767. The next prime is 672401783. The reversal of 672401781 is 187104276.

It can be written as a sum of positive squares in only one way, i.e., 421686225 + 250715556 = 20535^2 + 15834^2 .

It is not a de Polignac number, because 672401781 - 2⁹ = 672401269 is a prime.

It is a super-2 number, since 2×672401781² = 904248310183943922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (672401783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37355646 + ... + 37355663.

It is an arithmetic number, because the mean of its divisors is an integer number (161874505).

Almost surely, 2^672401781 is an apocalyptic number.

It is an amenable number.

672401781 is a deficient number, since it is larger than the sum of its proper divisors (298845249).

672401781 is a wasteful number, since it uses less digits than its factorization.

672401781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74711315 (or 74711312 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 672401781 is about 25930.7111549221. The cubic root of 672401781 is about 876.0783574432.

The spelling of 672401781 in words is "six hundred seventy-two million, four hundred one thousand, seven hundred eighty-one".